I think Parasol Up/Down is the best Lounge Bar in the City!
The experience here was fun; we had the opportunity to sit outside (after waiting at the inside bar for like 20min) to enjoy our wine and to watch their complimentary shows; service was very nice because the girls were all very friendly.
They offer snacks so it would better to eat something first before coming here; we stayed for a good 2hrs and left with happiness.
We'll be back here when we visit Vegas again; it's a great place to relax with a drink or two.